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    <title>Document</title>
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<script>
    // (1)  求i和sum的最终结果 
    // var i = 10;
    // var sum = i++ + ++i + i++ * 2 + i--;
    // console.log(i,sum);
    
    // (2)  
    var i = 13;
    
    // i      12    13    14          15
    var sum = i-- + i++ + ++i * 2 +  ++i;
    // sum    13    12    14 * 2     15  => 68
    console.log(i,sum);
    




</script>
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